161656775017 has 4 divisors (see below), whose sum is σ = 161936943316. Its totient is φ = 161376606720.

The previous prime is 161656774991. The next prime is 161656775101. The reversal of 161656775017 is 710577656161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 158178016656 + 3478758361 = 397716^2 + 58981^2 .

It is a cyclic number.

It is not a de Polignac number, because 161656775017 - 2¹⁹ = 161656250729 is a prime.

It is a super-2 number, since 2×161656775017² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161656775317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140083284 + ... + 140084437.

It is an arithmetic number, because the mean of its divisors is an integer number (40484235829).

Almost surely, 2^161656775017 is an apocalyptic number.

It is an amenable number.

161656775017 is a deficient number, since it is larger than the sum of its proper divisors (280168299).

161656775017 is an equidigital number, since it uses as much as digits as its factorization.

161656775017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280168298.

The product of its (nonzero) digits is 1852200, while the sum is 52.

The spelling of 161656775017 in words is "one hundred sixty-one billion, six hundred fifty-six million, seven hundred seventy-five thousand, seventeen".